/*-------------------------------------------------------------------------
 *
 * pg_proc.c
 *      routines to support manipulation of the pg_proc relation
 *
 * Portions Copyright (c) 2012-2014, TransLattice, Inc.
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * This source code file contains modifications made by THL A29 Limited ("Tencent Modifications").
 * All Tencent Modifications are Copyright (C) 2023 THL A29 Limited.
 *
 * IDENTIFICATION
 *      src/backend/catalog/pg_proc.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/htup_details.h"
#include "access/xact.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_language.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_proc_fn.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "executor/functions.h"
#include "funcapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_type.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/regproc.h"
#include "utils/rel.h"
#include "utils/syscache.h"
#ifdef PGXC
#include "pgxc/execRemote.h"
#include "pgxc/pgxc.h"
#include "pgxc/planner.h"
#endif


typedef struct
{
    char       *proname;
    char       *prosrc;
} parse_error_callback_arg;

static void sql_function_parse_error_callback(void *arg);
static int match_prosrc_to_query(const char *prosrc, const char *queryText,
                      int cursorpos);
static bool match_prosrc_to_literal(const char *prosrc, const char *literal,
                        int cursorpos, int *newcursorpos);


/* ----------------------------------------------------------------
 *        ProcedureCreate
 *
 * Note: allParameterTypes, parameterModes, parameterNames, trftypes, and proconfig
 * are either arrays of the proper types or NULL.  We declare them Datum,
 * not "ArrayType *", to avoid importing array.h into pg_proc_fn.h.
 * ----------------------------------------------------------------
 */
ObjectAddress
ProcedureCreate(const char *procedureName,
                Oid procNamespace,
                bool replace,
                bool returnsSet,
                Oid returnType,
                Oid proowner,
                Oid languageObjectId,
                Oid languageValidator,
                const char *prosrc,
                const char *probin,
                bool isAgg,
                bool isWindowFunc,
                bool security_definer,
                bool isLeakProof,
                bool isStrict,
                char volatility,
                char parallel,
                oidvector *parameterTypes,
                Datum allParameterTypes,
                Datum parameterModes,
                Datum parameterNames,
                List *parameterDefaults,
                Datum trftypes,
                Datum proconfig,
                float4 procost,
                float4 prorows)
{// #lizard forgives
    Oid            retval;
    int            parameterCount;
    int            allParamCount;
    Oid           *allParams;
    char       *paramModes = NULL;
    bool        genericInParam = false;
    bool        genericOutParam = false;
    bool        anyrangeInParam = false;
    bool        anyrangeOutParam = false;
    bool        internalInParam = false;
    bool        internalOutParam = false;
    Oid            variadicType = InvalidOid;
    Acl           *proacl = NULL;
    Relation    rel;
    HeapTuple    tup;
    HeapTuple    oldtup;
    bool        nulls[Natts_pg_proc];
    Datum        values[Natts_pg_proc];
    bool        replaces[Natts_pg_proc];
    Oid            relid;
    NameData    procname;
    TupleDesc    tupDesc;
    bool        is_update;
    ObjectAddress myself,
                referenced;
    int            i;
    Oid            trfid;

    /*
     * sanity checks
     */
    Assert(PointerIsValid(prosrc));

    parameterCount = parameterTypes->dim1;
    if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
        ereport(ERROR,
                (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
                 errmsg_plural("functions cannot have more than %d argument",
                               "functions cannot have more than %d arguments",
                               FUNC_MAX_ARGS,
                               FUNC_MAX_ARGS)));
    /* note: the above is correct, we do NOT count output arguments */

    /* Deconstruct array inputs */
    if (allParameterTypes != PointerGetDatum(NULL))
    {
        /*
         * We expect the array to be a 1-D OID array; verify that. We don't
         * need to use deconstruct_array() since the array data is just going
         * to look like a C array of OID values.
         */
        ArrayType  *allParamArray = (ArrayType *) DatumGetPointer(allParameterTypes);

        allParamCount = ARR_DIMS(allParamArray)[0];
        if (ARR_NDIM(allParamArray) != 1 ||
            allParamCount <= 0 ||
            ARR_HASNULL(allParamArray) ||
            ARR_ELEMTYPE(allParamArray) != OIDOID)
            elog(ERROR, "allParameterTypes is not a 1-D Oid array");
        allParams = (Oid *) ARR_DATA_PTR(allParamArray);
        Assert(allParamCount >= parameterCount);
        /* we assume caller got the contents right */
    }
    else
    {
        allParamCount = parameterCount;
        allParams = parameterTypes->values;
    }

    if (parameterModes != PointerGetDatum(NULL))
    {
        /*
         * We expect the array to be a 1-D CHAR array; verify that. We don't
         * need to use deconstruct_array() since the array data is just going
         * to look like a C array of char values.
         */
        ArrayType  *modesArray = (ArrayType *) DatumGetPointer(parameterModes);

        if (ARR_NDIM(modesArray) != 1 ||
            ARR_DIMS(modesArray)[0] != allParamCount ||
            ARR_HASNULL(modesArray) ||
            ARR_ELEMTYPE(modesArray) != CHAROID)
            elog(ERROR, "parameterModes is not a 1-D char array");
        paramModes = (char *) ARR_DATA_PTR(modesArray);
    }

    /*
     * Detect whether we have polymorphic or INTERNAL arguments.  The first
     * loop checks input arguments, the second output arguments.
     */
    for (i = 0; i < parameterCount; i++)
    {
        switch (parameterTypes->values[i])
        {
            case ANYARRAYOID:
            case ANYELEMENTOID:
            case ANYNONARRAYOID:
            case ANYENUMOID:
                genericInParam = true;
                break;
            case ANYRANGEOID:
                genericInParam = true;
                anyrangeInParam = true;
                break;
            case INTERNALOID:
                internalInParam = true;
                break;
        }
    }

    if (allParameterTypes != PointerGetDatum(NULL))
    {
        for (i = 0; i < allParamCount; i++)
        {
            if (paramModes == NULL ||
                paramModes[i] == PROARGMODE_IN ||
                paramModes[i] == PROARGMODE_VARIADIC)
                continue;        /* ignore input-only params */

            switch (allParams[i])
            {
                case ANYARRAYOID:
                case ANYELEMENTOID:
                case ANYNONARRAYOID:
                case ANYENUMOID:
                    genericOutParam = true;
                    break;
                case ANYRANGEOID:
                    genericOutParam = true;
                    anyrangeOutParam = true;
                    break;
                case INTERNALOID:
                    internalOutParam = true;
                    break;
            }
        }
    }

    /*
     * Do not allow polymorphic return type unless at least one input argument
     * is polymorphic.  ANYRANGE return type is even stricter: must have an
     * ANYRANGE input (since we can't deduce the specific range type from
     * ANYELEMENT).  Also, do not allow return type INTERNAL unless at least
     * one input argument is INTERNAL.
     */
    if ((IsPolymorphicType(returnType) || genericOutParam)
        && !genericInParam)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("cannot determine result data type"),
                 errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));

    if ((returnType == ANYRANGEOID || anyrangeOutParam) &&
        !anyrangeInParam)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("cannot determine result data type"),
                 errdetail("A function returning \"anyrange\" must have at least one \"anyrange\" argument.")));

    if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("unsafe use of pseudo-type \"internal\""),
                 errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));

    /*
     * don't allow functions of complex types that have the same name as
     * existing attributes of the type
     */
    if (parameterCount == 1 &&
        OidIsValid(parameterTypes->values[0]) &&
        (relid = typeidTypeRelid(parameterTypes->values[0])) != InvalidOid &&
        get_attnum(relid, procedureName) != InvalidAttrNumber)
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_COLUMN),
                 errmsg("\"%s\" is already an attribute of type %s",
                        procedureName,
                        format_type_be(parameterTypes->values[0]))));

    if (paramModes != NULL)
    {
        /*
         * Only the last input parameter can be variadic; if it is, save its
         * element type.  Errors here are just elog since caller should have
         * checked this already.
         */
        for (i = 0; i < allParamCount; i++)
        {
            switch (paramModes[i])
            {
                case PROARGMODE_IN:
                case PROARGMODE_INOUT:
                    if (OidIsValid(variadicType))
                        elog(ERROR, "variadic parameter must be last");
                    break;
                case PROARGMODE_OUT:
                case PROARGMODE_TABLE:
                    /* okay */
                    break;
                case PROARGMODE_VARIADIC:
                    if (OidIsValid(variadicType))
                        elog(ERROR, "variadic parameter must be last");
                    switch (allParams[i])
                    {
                        case ANYOID:
                            variadicType = ANYOID;
                            break;
                        case ANYARRAYOID:
                            variadicType = ANYELEMENTOID;
                            break;
                        default:
                            variadicType = get_element_type(allParams[i]);
                            if (!OidIsValid(variadicType))
                                elog(ERROR, "variadic parameter is not an array");
                            break;
                    }
                    break;
                default:
                    elog(ERROR, "invalid parameter mode '%c'", paramModes[i]);
                    break;
            }
        }
    }

    /*
     * All seems OK; prepare the data to be inserted into pg_proc.
     */

    for (i = 0; i < Natts_pg_proc; ++i)
    {
        nulls[i] = false;
        values[i] = (Datum) 0;
        replaces[i] = true;
    }

    namestrcpy(&procname, procedureName);
    values[Anum_pg_proc_proname - 1] = NameGetDatum(&procname);
    values[Anum_pg_proc_pronamespace - 1] = ObjectIdGetDatum(procNamespace);
    values[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(proowner);
    values[Anum_pg_proc_prolang - 1] = ObjectIdGetDatum(languageObjectId);
    values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
    values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
    values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
    values[Anum_pg_proc_protransform - 1] = ObjectIdGetDatum(InvalidOid);
    values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
    values[Anum_pg_proc_proiswindow - 1] = BoolGetDatum(isWindowFunc);
    values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
    values[Anum_pg_proc_proleakproof - 1] = BoolGetDatum(isLeakProof);
    values[Anum_pg_proc_proisstrict - 1] = BoolGetDatum(isStrict);
    values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
    values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
    values[Anum_pg_proc_proparallel - 1] = CharGetDatum(parallel);
    values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
    values[Anum_pg_proc_pronargdefaults - 1] = UInt16GetDatum(list_length(parameterDefaults));
    values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
    values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
    if (allParameterTypes != PointerGetDatum(NULL))
        values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
    else
        nulls[Anum_pg_proc_proallargtypes - 1] = true;
    if (parameterModes != PointerGetDatum(NULL))
        values[Anum_pg_proc_proargmodes - 1] = parameterModes;
    else
        nulls[Anum_pg_proc_proargmodes - 1] = true;
    if (parameterNames != PointerGetDatum(NULL))
        values[Anum_pg_proc_proargnames - 1] = parameterNames;
    else
        nulls[Anum_pg_proc_proargnames - 1] = true;
    if (parameterDefaults != NIL)
        values[Anum_pg_proc_proargdefaults - 1] = CStringGetTextDatum(nodeToString(parameterDefaults));
    else
        nulls[Anum_pg_proc_proargdefaults - 1] = true;
    if (trftypes != PointerGetDatum(NULL))
        values[Anum_pg_proc_protrftypes - 1] = trftypes;
    else
        nulls[Anum_pg_proc_protrftypes - 1] = true;
    values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
    if (probin)
        values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
    else
        nulls[Anum_pg_proc_probin - 1] = true;
    if (proconfig != PointerGetDatum(NULL))
        values[Anum_pg_proc_proconfig - 1] = proconfig;
    else
        nulls[Anum_pg_proc_proconfig - 1] = true;
    /* proacl will be determined later */

    rel = heap_open(ProcedureRelationId, RowExclusiveLock);
    tupDesc = RelationGetDescr(rel);

    /* Check for pre-existing definition */
    oldtup = SearchSysCache3(PROCNAMEARGSNSP,
                             PointerGetDatum(procedureName),
                             PointerGetDatum(parameterTypes),
                             ObjectIdGetDatum(procNamespace));

    if (HeapTupleIsValid(oldtup))
    {
        /* There is one; okay to replace it? */
        Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
        Datum        proargnames;
        bool        isnull;

        if (!replace)
            ereport(ERROR,
                    (errcode(ERRCODE_DUPLICATE_FUNCTION),
                     errmsg("function \"%s\" already exists with same argument types",
                            procedureName)));
        if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), proowner))
            aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
                           procedureName);

        /*
         * Not okay to change the return type of the existing proc, since
         * existing rules, views, etc may depend on the return type.
         */
        if (returnType != oldproc->prorettype ||
            returnsSet != oldproc->proretset)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                     errmsg("cannot change return type of existing function"),
                     errhint("Use DROP FUNCTION %s first.",
                             format_procedure(HeapTupleGetOid(oldtup)))));

        /*
         * If it returns RECORD, check for possible change of record type
         * implied by OUT parameters
         */
        if (returnType == RECORDOID)
        {
            TupleDesc    olddesc;
            TupleDesc    newdesc;

            olddesc = build_function_result_tupdesc_t(oldtup);
            newdesc = build_function_result_tupdesc_d(allParameterTypes,
                                                      parameterModes,
                                                      parameterNames);
            if (olddesc == NULL && newdesc == NULL)
                 /* ok, both are runtime-defined RECORDs */ ;
            else if (olddesc == NULL || newdesc == NULL ||
                     !equalTupleDescs(olddesc, newdesc))
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                         errmsg("cannot change return type of existing function"),
                         errdetail("Row type defined by OUT parameters is different."),
                         errhint("Use DROP FUNCTION %s first.",
                                 format_procedure(HeapTupleGetOid(oldtup)))));
        }

        /*
         * If there were any named input parameters, check to make sure the
         * names have not been changed, as this could break existing calls. We
         * allow adding names to formerly unnamed parameters, though.
         */
        proargnames = SysCacheGetAttr(PROCNAMEARGSNSP, oldtup,
                                      Anum_pg_proc_proargnames,
                                      &isnull);
        if (!isnull)
        {
            Datum        proargmodes;
            char      **old_arg_names;
            char      **new_arg_names;
            int            n_old_arg_names;
            int            n_new_arg_names;
            int            j;

            proargmodes = SysCacheGetAttr(PROCNAMEARGSNSP, oldtup,
                                          Anum_pg_proc_proargmodes,
                                          &isnull);
            if (isnull)
                proargmodes = PointerGetDatum(NULL);    /* just to be sure */

            n_old_arg_names = get_func_input_arg_names(proargnames,
                                                       proargmodes,
                                                       &old_arg_names);
            n_new_arg_names = get_func_input_arg_names(parameterNames,
                                                       parameterModes,
                                                       &new_arg_names);
            for (j = 0; j < n_old_arg_names; j++)
            {
                if (old_arg_names[j] == NULL)
                    continue;
                if (j >= n_new_arg_names || new_arg_names[j] == NULL ||
                    strcmp(old_arg_names[j], new_arg_names[j]) != 0)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                             errmsg("cannot change name of input parameter \"%s\"",
                                    old_arg_names[j]),
                             errhint("Use DROP FUNCTION %s first.",
                                     format_procedure(HeapTupleGetOid(oldtup)))));
            }
        }

        /*
         * If there are existing defaults, check compatibility: redefinition
         * must not remove any defaults nor change their types.  (Removing a
         * default might cause a function to fail to satisfy an existing call.
         * Changing type would only be possible if the associated parameter is
         * polymorphic, and in such cases a change of default type might alter
         * the resolved output type of existing calls.)
         */
        if (oldproc->pronargdefaults != 0)
        {
            Datum        proargdefaults;
            List       *oldDefaults;
            ListCell   *oldlc;
            ListCell   *newlc;

            if (list_length(parameterDefaults) < oldproc->pronargdefaults)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                         errmsg("cannot remove parameter defaults from existing function"),
                         errhint("Use DROP FUNCTION %s first.",
                                 format_procedure(HeapTupleGetOid(oldtup)))));

            proargdefaults = SysCacheGetAttr(PROCNAMEARGSNSP, oldtup,
                                             Anum_pg_proc_proargdefaults,
                                             &isnull);
            Assert(!isnull);
            oldDefaults = castNode(List, stringToNode(TextDatumGetCString(proargdefaults)));
            Assert(list_length(oldDefaults) == oldproc->pronargdefaults);

            /* new list can have more defaults than old, advance over 'em */
            newlc = list_head(parameterDefaults);
            for (i = list_length(parameterDefaults) - oldproc->pronargdefaults;
                 i > 0;
                 i--)
                newlc = lnext(newlc);

            foreach(oldlc, oldDefaults)
            {
                Node       *oldDef = (Node *) lfirst(oldlc);
                Node       *newDef = (Node *) lfirst(newlc);

                if (exprType(oldDef) != exprType(newDef))
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                             errmsg("cannot change data type of existing parameter default value"),
                             errhint("Use DROP FUNCTION %s first.",
                                     format_procedure(HeapTupleGetOid(oldtup)))));
                newlc = lnext(newlc);
            }
        }

        /* Can't change aggregate or window-function status, either */
        if (oldproc->proisagg != isAgg)
        {
            if (oldproc->proisagg)
                ereport(ERROR,
                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                         errmsg("function \"%s\" is an aggregate function",
                                procedureName)));
            else
                ereport(ERROR,
                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                         errmsg("function \"%s\" is not an aggregate function",
                                procedureName)));
        }
        if (oldproc->proiswindow != isWindowFunc)
        {
            if (oldproc->proiswindow)
                ereport(ERROR,
                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                         errmsg("function \"%s\" is a window function",
                                procedureName)));
            else
                ereport(ERROR,
                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                         errmsg("function \"%s\" is not a window function",
                                procedureName)));
        }

        /*
         * Do not change existing ownership or permissions, either.  Note
         * dependency-update code below has to agree with this decision.
         */
        replaces[Anum_pg_proc_proowner - 1] = false;
        replaces[Anum_pg_proc_proacl - 1] = false;

        /* Okay, do it... */
        tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
        CatalogTupleUpdate(rel, &tup->t_self, tup);

        ReleaseSysCache(oldtup);
        is_update = true;
    }
    else
    {
        /* Creating a new procedure */

        /* First, get default permissions and set up proacl */
        proacl = get_user_default_acl(ACL_OBJECT_FUNCTION, proowner,
                                      procNamespace);
        if (proacl != NULL)
            values[Anum_pg_proc_proacl - 1] = PointerGetDatum(proacl);
        else
            nulls[Anum_pg_proc_proacl - 1] = true;

        tup = heap_form_tuple(tupDesc, values, nulls);
        CatalogTupleInsert(rel, tup);
        is_update = false;
    }


    retval = HeapTupleGetOid(tup);

    /*
     * Create dependencies for the new function.  If we are updating an
     * existing function, first delete any existing pg_depend entries.
     * (However, since we are not changing ownership or permissions, the
     * shared dependencies do *not* need to change, and we leave them alone.)
     */
    if (is_update)
        deleteDependencyRecordsFor(ProcedureRelationId, retval, true);

    myself.classId = ProcedureRelationId;
    myself.objectId = retval;
    myself.objectSubId = 0;

    /* dependency on namespace */
    referenced.classId = NamespaceRelationId;
    referenced.objectId = procNamespace;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on implementation language */
    referenced.classId = LanguageRelationId;
    referenced.objectId = languageObjectId;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on return type */
    referenced.classId = TypeRelationId;
    referenced.objectId = returnType;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on transform used by return type, if any */
    if ((trfid = get_transform_oid(returnType, languageObjectId, true)))
    {
        referenced.classId = TransformRelationId;
        referenced.objectId = trfid;
        referenced.objectSubId = 0;
        recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
    }

    /* dependency on parameter types */
    for (i = 0; i < allParamCount; i++)
    {
        referenced.classId = TypeRelationId;
        referenced.objectId = allParams[i];
        referenced.objectSubId = 0;
        recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

        /* dependency on transform used by parameter type, if any */
        if ((trfid = get_transform_oid(allParams[i], languageObjectId, true)))
        {
            referenced.classId = TransformRelationId;
            referenced.objectId = trfid;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
        }
    }

    /* dependency on parameter default expressions */
    if (parameterDefaults)
        recordDependencyOnExpr(&myself, (Node *) parameterDefaults,
                               NIL, DEPENDENCY_NORMAL);

    /* dependency on owner */
    if (!is_update)
        recordDependencyOnOwner(ProcedureRelationId, retval, proowner);

    /* dependency on any roles mentioned in ACL */
    if (!is_update && proacl != NULL)
    {
        int            nnewmembers;
        Oid           *newmembers;

        nnewmembers = aclmembers(proacl, &newmembers);
        updateAclDependencies(ProcedureRelationId, retval, 0,
                              proowner,
                              0, NULL,
                              nnewmembers, newmembers);
    }

    /* dependency on extension */
    recordDependencyOnCurrentExtension(&myself, is_update);

    heap_freetuple(tup);

    /* Post creation hook for new function */
    InvokeObjectPostCreateHook(ProcedureRelationId, retval, 0);

    heap_close(rel, RowExclusiveLock);

    /* Verify function body */
    if (OidIsValid(languageValidator))
    {
        ArrayType  *set_items = NULL;
        int            save_nestlevel = 0;

        /* Advance command counter so new tuple can be seen by validator */
        CommandCounterIncrement();

        /*
         * Set per-function configuration parameters so that the validation is
         * done with the environment the function expects.  However, if
         * check_function_bodies is off, we don't do this, because that would
         * create dump ordering hazards that pg_dump doesn't know how to deal
         * with.  (For example, a SET clause might refer to a not-yet-created
         * text search configuration.)    This means that the validator
         * shouldn't complain about anything that might depend on a GUC
         * parameter when check_function_bodies is off.
         */
        if (check_function_bodies)
        {
            set_items = (ArrayType *) DatumGetPointer(proconfig);
            if (set_items)        /* Need a new GUC nesting level */
            {
                save_nestlevel = NewGUCNestLevel();
                ProcessGUCArray(set_items,
                                (superuser() ? PGC_SUSET : PGC_USERSET),
                                PGC_S_SESSION,
                                GUC_ACTION_SAVE);
            }
        }

        OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));

        if (set_items)
            AtEOXact_GUC(true, save_nestlevel);
    }

    return myself;
}



/*
 * Validator for internal functions
 *
 * Check that the given internal function name (the "prosrc" value) is
 * a known builtin function.
 */
Datum
fmgr_internal_validator(PG_FUNCTION_ARGS)
{
    Oid            funcoid = PG_GETARG_OID(0);
    HeapTuple    tuple;
    bool        isnull;
    Datum        tmp;
    char       *prosrc;

    if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
        PG_RETURN_VOID();

    /*
     * We do not honor check_function_bodies since it's unlikely the function
     * name will be found later if it isn't there now.
     */

    tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "cache lookup failed for function %u", funcoid);

    tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
    if (isnull)
        elog(ERROR, "null prosrc");
    prosrc = TextDatumGetCString(tmp);

    if (fmgr_internal_function(prosrc) == InvalidOid)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_FUNCTION),
                 errmsg("there is no built-in function named \"%s\"",
                        prosrc)));

    ReleaseSysCache(tuple);

    PG_RETURN_VOID();
}



/*
 * Validator for C language functions
 *
 * Make sure that the library file exists, is loadable, and contains
 * the specified link symbol. Also check for a valid function
 * information record.
 */
Datum
fmgr_c_validator(PG_FUNCTION_ARGS)
{
    Oid            funcoid = PG_GETARG_OID(0);
    void       *libraryhandle;
    HeapTuple    tuple;
    bool        isnull;
    Datum        tmp;
    char       *prosrc;
    char       *probin;

    if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
        PG_RETURN_VOID();

    /*
     * It'd be most consistent to skip the check if !check_function_bodies,
     * but the purpose of that switch is to be helpful for pg_dump loading,
     * and for pg_dump loading it's much better if we *do* check.
     */

    tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "cache lookup failed for function %u", funcoid);

    tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
    if (isnull)
        elog(ERROR, "null prosrc for C function %u", funcoid);
    prosrc = TextDatumGetCString(tmp);

    tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
    if (isnull)
        elog(ERROR, "null probin for C function %u", funcoid);
    probin = TextDatumGetCString(tmp);

    (void) load_external_function(probin, prosrc, true, &libraryhandle);
    (void) fetch_finfo_record(libraryhandle, prosrc);

    ReleaseSysCache(tuple);

    PG_RETURN_VOID();
}


/*
 * Validator for SQL language functions
 *
 * Parse it here in order to be sure that it contains no syntax errors.
 */
Datum
fmgr_sql_validator(PG_FUNCTION_ARGS)
{// #lizard forgives
    Oid            funcoid = PG_GETARG_OID(0);
    HeapTuple    tuple;
    Form_pg_proc proc;
    List       *raw_parsetree_list;
    List       *querytree_list;
    ListCell   *lc;
    bool        isnull;
    Datum        tmp;
    char       *prosrc;
    parse_error_callback_arg callback_arg;
    ErrorContextCallback sqlerrcontext;
    bool        haspolyarg;
    int            i;

    if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
        PG_RETURN_VOID();

    tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "cache lookup failed for function %u", funcoid);
    proc = (Form_pg_proc) GETSTRUCT(tuple);

    /* Disallow pseudotype result */
    /* except for RECORD, VOID, or polymorphic */
    if (get_typtype(proc->prorettype) == TYPTYPE_PSEUDO &&
        proc->prorettype != RECORDOID &&
        proc->prorettype != VOIDOID &&
        !IsPolymorphicType(proc->prorettype))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("SQL functions cannot return type %s",
                        format_type_be(proc->prorettype))));

    /* Disallow pseudotypes in arguments */
    /* except for polymorphic */
    haspolyarg = false;
    for (i = 0; i < proc->pronargs; i++)
    {
        if (get_typtype(proc->proargtypes.values[i]) == TYPTYPE_PSEUDO)
        {
            if (IsPolymorphicType(proc->proargtypes.values[i]))
                haspolyarg = true;
            else
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                         errmsg("SQL functions cannot have arguments of type %s",
                                format_type_be(proc->proargtypes.values[i]))));
        }
    }

    /* Postpone body checks if !check_function_bodies */
    if (check_function_bodies)
    {
        tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
        if (isnull)
            elog(ERROR, "null prosrc");

        prosrc = TextDatumGetCString(tmp);

        /*
         * Setup error traceback support for ereport().
         */
        callback_arg.proname = NameStr(proc->proname);
        callback_arg.prosrc = prosrc;

        sqlerrcontext.callback = sql_function_parse_error_callback;
        sqlerrcontext.arg = (void *) &callback_arg;
        sqlerrcontext.previous = error_context_stack;
        error_context_stack = &sqlerrcontext;

        /*
         * We can't do full prechecking of the function definition if there
         * are any polymorphic input types, because actual datatypes of
         * expression results will be unresolvable.  The check will be done at
         * runtime instead.
         *
         * We can run the text through the raw parser though; this will at
         * least catch silly syntactic errors.
         */
        raw_parsetree_list = pg_parse_query(prosrc);

        if (!haspolyarg)
        {
            /*
             * OK to do full precheck: analyze and rewrite the queries, then
             * verify the result type.
             */
            SQLFunctionParseInfoPtr pinfo;

            /* But first, set up parameter information */
            pinfo = prepare_sql_fn_parse_info(tuple, NULL, InvalidOid);

            querytree_list = NIL;
            foreach(lc, raw_parsetree_list)
            {
                RawStmt    *parsetree = lfirst_node(RawStmt, lc);
                List       *querytree_sublist;

                Assert(IsA(parsetree, RawStmt));

#ifdef PGXC
                /* Block CTAS in SQL functions */
                if (IsA(parsetree->stmt, CreateTableAsStmt))
                    ereport(ERROR,
                            (errcode(ERRCODE_SYNTAX_ERROR),
                            errmsg("In XC, SQL functions cannot contain utility statements")));
#endif

                querytree_sublist = pg_analyze_and_rewrite_params(parsetree,
                                                                  prosrc,
                                                                  (ParserSetupHook) sql_fn_parser_setup,
                                                                  pinfo,
                                                                  NULL);
                querytree_list = list_concat(querytree_list,
                                             querytree_sublist);
            }

            (void) check_sql_fn_retval(funcoid, proc->prorettype,
                                       querytree_list,
                                       NULL, NULL);
        }

        error_context_stack = sqlerrcontext.previous;
    }

    ReleaseSysCache(tuple);

    PG_RETURN_VOID();
}

/*
 * Error context callback for handling errors in SQL function definitions
 */
static void
sql_function_parse_error_callback(void *arg)
{
    parse_error_callback_arg *callback_arg = (parse_error_callback_arg *) arg;

    /* See if it's a syntax error; if so, transpose to CREATE FUNCTION */
    if (!function_parse_error_transpose(callback_arg->prosrc))
    {
        /* If it's not a syntax error, push info onto context stack */
        errcontext("SQL function \"%s\"", callback_arg->proname);
    }
}

/*
 * Adjust a syntax error occurring inside the function body of a CREATE
 * FUNCTION or DO command.  This can be used by any function validator or
 * anonymous-block handler, not only for SQL-language functions.
 * It is assumed that the syntax error position is initially relative to the
 * function body string (as passed in).  If possible, we adjust the position
 * to reference the original command text; if we can't manage that, we set
 * up an "internal query" syntax error instead.
 *
 * Returns true if a syntax error was processed, false if not.
 */
bool
function_parse_error_transpose(const char *prosrc)
{
    int            origerrposition;
    int            newerrposition;
    const char *queryText;

    /*
     * Nothing to do unless we are dealing with a syntax error that has a
     * cursor position.
     *
     * Some PLs may prefer to report the error position as an internal error
     * to begin with, so check that too.
     */
    origerrposition = geterrposition();
    if (origerrposition <= 0)
    {
        origerrposition = getinternalerrposition();
        if (origerrposition <= 0)
            return false;
    }

    /* We can get the original query text from the active portal (hack...) */
    Assert(ActivePortal && ActivePortal->status == PORTAL_ACTIVE);
    queryText = ActivePortal->sourceText;

    /* Try to locate the prosrc in the original text */
    newerrposition = match_prosrc_to_query(prosrc, queryText, origerrposition);

    if (newerrposition > 0)
    {
        /* Successful, so fix error position to reference original query */
        errposition(newerrposition);
        /* Get rid of any report of the error as an "internal query" */
        internalerrposition(0);
        internalerrquery(NULL);
    }
    else
    {
        /*
         * If unsuccessful, convert the position to an internal position
         * marker and give the function text as the internal query.
         */
        errposition(0);
        internalerrposition(origerrposition);
        internalerrquery(prosrc);
    }

    return true;
}

/*
 * Try to locate the string literal containing the function body in the
 * given text of the CREATE FUNCTION or DO command.  If successful, return
 * the character (not byte) index within the command corresponding to the
 * given character index within the literal.  If not successful, return 0.
 */
static int
match_prosrc_to_query(const char *prosrc, const char *queryText,
                      int cursorpos)
{// #lizard forgives
    /*
     * Rather than fully parsing the original command, we just scan the
     * command looking for $prosrc$ or 'prosrc'.  This could be fooled (though
     * not in any very probable scenarios), so fail if we find more than one
     * match.
     */
    int            prosrclen = strlen(prosrc);
    int            querylen = strlen(queryText);
    int            matchpos = 0;
    int            curpos;
    int            newcursorpos;

    for (curpos = 0; curpos < querylen - prosrclen; curpos++)
    {
        if (queryText[curpos] == '$' &&
            strncmp(prosrc, &queryText[curpos + 1], prosrclen) == 0 &&
            queryText[curpos + 1 + prosrclen] == '$')
        {
            /*
             * Found a $foo$ match.  Since there are no embedded quoting
             * characters in a dollar-quoted literal, we don't have to do any
             * fancy arithmetic; just offset by the starting position.
             */
            if (matchpos)
                return 0;        /* multiple matches, fail */
            matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
                + cursorpos;
        }
        else if (queryText[curpos] == '\'' &&
                 match_prosrc_to_literal(prosrc, &queryText[curpos + 1],
                                         cursorpos, &newcursorpos))
        {
            /*
             * Found a 'foo' match.  match_prosrc_to_literal() has adjusted
             * for any quotes or backslashes embedded in the literal.
             */
            if (matchpos)
                return 0;        /* multiple matches, fail */
            matchpos = pg_mbstrlen_with_len(queryText, curpos + 1)
                + newcursorpos;
        }
    }

    return matchpos;
}

/*
 * Try to match the given source text to a single-quoted literal.
 * If successful, adjust newcursorpos to correspond to the character
 * (not byte) index corresponding to cursorpos in the source text.
 *
 * At entry, literal points just past a ' character.  We must check for the
 * trailing quote.
 */
static bool
match_prosrc_to_literal(const char *prosrc, const char *literal,
                        int cursorpos, int *newcursorpos)
{// #lizard forgives
    int            newcp = cursorpos;
    int            chlen;

    /*
     * This implementation handles backslashes and doubled quotes in the
     * string literal.  It does not handle the SQL syntax for literals
     * continued across line boundaries.
     *
     * We do the comparison a character at a time, not a byte at a time, so
     * that we can do the correct cursorpos math.
     */
    while (*prosrc)
    {
        cursorpos--;            /* characters left before cursor */

        /*
         * Check for backslashes and doubled quotes in the literal; adjust
         * newcp when one is found before the cursor.
         */
        if (*literal == '\\')
        {
            literal++;
            if (cursorpos > 0)
                newcp++;
        }
        else if (*literal == '\'')
        {
            if (literal[1] != '\'')
                goto fail;
            literal++;
            if (cursorpos > 0)
                newcp++;
        }
        chlen = pg_mblen(prosrc);
        if (strncmp(prosrc, literal, chlen) != 0)
            goto fail;
        prosrc += chlen;
        literal += chlen;
    }

    if (*literal == '\'' && literal[1] != '\'')
    {
        /* success */
        *newcursorpos = newcp;
        return true;
    }

fail:
    /* Must set *newcursorpos to suppress compiler warning */
    *newcursorpos = newcp;
    return false;
}

List *
oid_array_to_list(Datum datum)
{
    ArrayType  *array = DatumGetArrayTypeP(datum);
    Datum       *values;
    int            nelems;
    int            i;
    List       *result = NIL;

    deconstruct_array(array,
                      OIDOID,
                      sizeof(Oid), true, 'i',
                      &values, NULL, &nelems);
    for (i = 0; i < nelems; i++)
        result = lappend_oid(result, values[i]);
    return result;
}
